High-viscosity fire suppressant delivery system using an injection quill

ABSTRACT

A system for delivering an additive into a fluid stream is disclosed that addresses the issues of delivering a pressurized stream of a shear thickening or dilatant material which is commonly used for fire suppression. The system uses a positive displacement pump that is controlled to deliver the additive to a fluid stream in the correct ratio according to fluid flow rates. The system also incorporates an injection quill for delivering the additive to the fluid stream within a dispensing line. The injection quill includes an internal extension within its valve chamber, and the internal extension provides ports that allow for improved fluid flow of dilatant material.

FIELD

The present disclosure relates generally to a system for delivering afire suppressant. More particularly, the disclosure is directed to usingan improved injection quill in a fire suppressant delivery system.

BACKGROUND

Fire suppressants can have a high viscosity or be a dilatant materialthat allows the fire suppressant to adhere to vertical surfaces. Highviscosity makes delivery of the fire suppressant difficult. A dilatant(also termed shear thickening) material is one in which viscosityincreases with the rate of shear strain. Such a shear thickening fluid,also known by the acronym STF, is an example of a non-Newtonian fluid.

A shear thickening fluid is a fluid where the shear viscosity increaseswith applied shear stress. This behavior is only one type of deviationfrom Newton's Law, and it is controlled by such factors as particlesize, shape, and distribution. The properties of these suspensionsdepend on Hamaker theory and Van der Waals forces and can be stabilizedelectrostatically or sterically. Shear thickening behavior occurs when acolloidal suspension transitions from a stable state to a state offlocculation. Such behavior is currently being researched for use inbody armor applications by companies like Dow Corning with their ActiveProtection System. A large portion of the properties of these systemsare due to the surface chemistry of particles in dispersion, known ascolloids.

As is of course well known, the standard method of extinguishing urbanfires is to spray water, usually from hoses, onto the burning buildings,etc. Water is certainly an excellent extinguisher, but it does havecertain shortcomings. The most obvious of which is that, being afree-flowing liquid, it runs off vertical surfaces. To render a verticalwall sufficiently wet to be either noncombustible or at least difficultto combust, comparatively huge quantities of water must be applied toit. Additionally, the wetness which is imparted will tend to dissipaterapidly by evaporation and drain off. It obviously would be very usefulif water could be modified in some fashion so as to stick to verticalsurfaces and thereafter undergo comparatively limited loss byevaporation and runoff.

U.S. Pat. No. 3,719,515 teaches converging a stream of dilatant materialwith another solution immediately before or after dispersing, so thatupon convergence a viscous dilatant fire suppressant material is formed.The converging streams are achieved using adjacent or concentric nozzlessurrounding an inner nozzle. This approach avoids placing mechanicalstress on the dilatant solution but does not provide adequate mixing ofthe dilatant material with the solvent.

U.S. Pat. No. 3,848,802 also describes disadvantages of external mixing.The latter practice does not permit sufficient contact between themolecules of the reacting solutions to convert them into the dilatantmaterial in a highly efficient manner. Moreover, when external mixingmethods are employed, unreacted droplets of the solutions which do notevaporate before reaching the substrate wet the surface thereof andreduce the tendency of the dilatant material to adhere thereto. Stillfurther, with external mixing methods the direction and consistency ofthe spray of dilatant material is not easily controlled. For the abovereasons, preparation and application of the dilatant material has beenrelatively expensive.

Injection quills can be used for injecting a substance into a movingstream of fluid, such as water. A standard injection quill has a checkvalve with a large needle and thread on the end so it can be screwedinto a pipe and allow for injection of a material into the flow ofanother material. These standard quills are primarily used in watertreatment plants and were designed to work with chlorine and other lowviscosity materials. Standard injection quills are typically operatedwith around 3,000 psi injection pressure and are used to delivercorrosive chemicals.

These standard injection quills are unsuitable for delivering a highviscosity or dilatant fire suppressant. Firstly, the ports through thestandard injection quill are too small and required too much power topush the highly viscous material through the quill. The injection portis typically smaller than the input port, thus creating resistancethrough the quill. Secondly, the check valve ball would get pushed tothe bottom of the chamber and crush the spring at the bottom. Thinmaterials would not push the ball that far to the bottom and allow thethinner material to flow through the spring easily. Because the springis crushed flat, it creates a strainer that is very difficult to pushthe material through. In addition to the increased resistance, thecrushed spring would catch the larger particles suspended in thematerial and start to plug the quill. The longer it ran, the moreparticles it would catch, the more resistance in the quill and lessvolume would pass through. Eventually it would clog completely and jamthe pump motor. Finally, a standard injection quill is made of stainlesssteel and is press-fit assembled. This is unacceptable for delivery of aviscous fire suppressant as the injection quill will require periodicinspection and cleaning. Disassembly of a press fit quill is impossiblewithout destroying the ball and possibly the ball seat.

A cross-sectional view of standard prior art injection quill is shown inFIG. 1. The main body 10 and quill body 20 are connected by a press fit.Main body 10 can include threads 14, 16 on the outer surface to allowfor coupling with other pipes. The interior of the main body forms acheck valve chamber 30 containing a valve ball 40 and valve spring 50.In operation, fluid enters main body 10 through input port 12 andimpinges upon valve ball 40 forcing valve spring 50 to compress to allowfluid to flow from input port 12 to quill body 20 through the compressedvalve spring 50 and out injection port 22. As noted above, the internaldiameter of injection port 22 is less than the internal diameter ofinput port 12 causing resistance through the injection quill. The end ofinjection port 22 is preferably angled so that the angled opening facesthe direction of fluid flow to limit the backpressure into the injectionquill.

SUMMARY

Accordingly, there is a need for a system for delivering high-viscosityor dilatant additive material such as fire suppressants.

According to a first aspect, a system for delivering an additive into afluid stream is disclosed that includes a positive displacement pumpcoupled to an additive source containing the additive. The positivedisplacement pump pumps the additive through an additive dispensing lineinto an injection quill coupled to a water dispensing line. A variablespeed motor is coupled to the positive displacement pump to drive thepositive displacement pump. A flow meter is coupled to the waterdispensing line prior to the injection quill to determine the water flowrate which is used by a controller to control a rate of injection fromthe additive injecting line into the water dispensing line bycontrolling the variable speed motor according to the water flow ratefrom the flow meter.

The positive displacement pump used with the additive can be a gear pumpor lobe pump to limit shocking of the dilatant material. Preferably, thefluid is water, and the fluid dispensing line can be coupled to a waterpump and water tank of a fire truck or coupled to a building watersupply, such as for a building fire sprinkler system. The controller canbe a programmable logic controller or other microprocessor-based system,and the controller can also include a motor controller.

The injection quill should include a check valve to prevent backflowinto the additive dispensing line. The check valve can have a checkvalve chamber, check valve ball, and a spring. The injection quill canalso have an extension extending into the check valve chamber, and thespring and check valve ball can be seated axially on the extension. Theextension can also define one or more apertures for providing fluidcoupling between the check valve chamber and an internal passage of theinjection quill to allow fluid to flow to the injection port of thequill. Some aspects can also include an inline mixer in the fluid lineafter the injection quill.

According to another aspect, an improved injection quill for injectingthe additive into a fluid stream is disclosed. The injection quillcomprises a main body having an input port for receiving the additive,and a check valve chamber formed within the main body coupled to theinput port. The check valve chamber contains a valve ball biased in aclosed position by a valve spring. The injection quill also comprises aquill body having an injection port for insertion into the fluid stream,and an internal extension that extends into check valve chamber, theinternal extension having at least one port that couples the check valvechamber to the injection port.

The internal extension of the injection quill can provide a seat forpositioning the valve spring on an end of the internal extension that isdisposed within the check valve chamber. The internal extension can alsohave an internal diameter at least as large as an internal diameter ofthe input port to limit fluid resistance through the injection quill.The main body can also include threading on an inner surface that mateswith threading on an outer surface of the quill body to allow forassembly and disassembly of the injection quill. A set screw can be usedretain the main body and the quill body in fixed engagement. The mainbody can have threading on the outer surface near an output port end ofthe main body and threading on the outer surface near an injection portend of the main body to allow for coupling the injection quill to anadditive dispensing line and a water dispensing line.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the various embodiments described hereinand to show more clearly how they may be carried into effect, referencewill now be made, by way of example only, to the accompanying drawingswhich show at least one exemplary embodiment, and in which:

FIG. 1 is a cross-sectional view of a prior art injection quill;

FIG. 2 is a block diagram showing an embodiment of a fire suppressantdelivery system;

FIG. 3 is a perspective view of an embodiment of an injection quill foruse in a fire suppressant delivery system;

FIG. 4 is a top view of the injection quill of FIG. 2;

FIG. 5 is a side view of the injection quill of FIG. 2; and

FIG. 6 is a cross-section view of the injection quill of FIG. 3 alongline A-A.

DESCRIPTION OF VARIOUS EMBODIMENTS

It will be appreciated that for simplicity and clarity of illustration,where considered appropriate, numerous specific details are set forth inorder to provide a thorough understanding of the exemplary embodimentsdescribed herein. However, it will be understood by those of ordinaryskill in the art that the embodiments described herein may be practicedwithout these specific details. In other instances, well-known methods,procedures and components have not been described in detail so as not toobscure the embodiments described herein. Furthermore, this descriptionis not to be considered as limiting the scope of the embodimentsdescribed herein in any way, but rather merely serves to provideexamples of some of the possible embodiments.

Reference is first made to FIG. 2, shown is a schematic diagram of anadditive delivery system 100. System 100 can be used for delivery ofdilatant fire suppressants into a fluid stream, such as water, forexample. System 100 could be a standalone system that includes both awater system and an additive system, or system 100 can be configured towork with other external water supply systems, such as with a fire truckor a building fire suppression system. Fire suppressant delivery system100 introduces a shear thickening fluid additive from additive source114 into a water stream provided by the water system prior to delivery.

Fire suppressant delivery system 100 includes an additive pump 112 thatis coupled to additive source 114 to pump the additive into additivedispensing line 113. A holding tank, reservoir, or feed systemcontaining the additive can act as additive source 114. Additive pump112 is selected to limit the shear thickening properties of the additivematerial. Preferably, a positive displacement rotary-type pump is used,such as a rotary-style gear pump, a lobe pump, or a rotary vane pump,for example. A positive displacement gear pump can provide a measurableand constant volume of additive material for each revolution of thepump. Using a positive displacement gear pump allows for a constant flowof additive at a given speed (revolutions per minute (RPM)) of additivepump 112. A piston or diaphragm pump is undesirable as it would shockthe additive material causing it to thicken and make it more difficultto inject the additive into the water stream.

Additive pump 112 can be coupled to a pump motor 116, and pump motor 116can be a variable speed motor controlled via motor controller 118 andRPM encoder 119. Control module 120 can receive the speed of pump motor116 from RPM encoder 119 and provide output to motor controller 118 toadjust the speed of pump motor 116, and thus the flow rate of theadditive being pumped from additive source 114. Control module 120 canalso be coupled to a flow meter 122 that measures the flow rate of thewater system (e.g. a paddle wheel flow meter). This allows controlmodule 120 to control the ratio of water to additive by increasing ordecreasing the speed of additive pump 112 based on the water flow ratefrom flow meter 122. In some embodiments, RPM encoder 119 and motorcontroller 118 can be integrated into pump motor 116. Other embodiments,can integrate the functionality of RPM encoder 119, motor controller118, and pump motor 116 directly with additive pump 112.

Additive dispensing line 113 can include a calibration valve 121 thatcan direct the additive to a calibration port to allow control module120 to determine the volume of additive supplied per revolution of pumpmotor 116. Preferably, calibration is performed prior to operation ofadditive delivery system 100.

Additive pump 112 can be driven by either an AC or a DC motor. Pumpmotor 118 is preferably using low speeds between 0 and 1800 RPM, and ispreferably a low horsepower motor, such as a ¾ or 1 horsepower motor. Insome embodiments, a programmable logic controller (PLC) can act ascontrol module 120 coupled to RPM encoder 119. In other embodimentscontrol module 120 can include other microprocessor-based controllers.

Motor controller 118 can be a variable-frequency drive or DC drive(voltage regulator) that can be coupled to control module 120 to controlthe speed of additive pump 112. Motor controller 118 can work witheither a DC or AC pump motor 116. Motor controller 118 can vary thefrequency or voltage, depending on the motor type, to control the speedof pump motor 116. Motor controller 118 can have a resistivecompensation feature that allows motor controller 118 to maintain aconstant speed regardless of the resistance to pump motor 116 fromadditive pump 112. As water pressure fluctuates in output waterdispensing line 130, it can become easier or harder to inject theadditive fire suppressant material. Motor controller 118 can compensatefor the fluctuation in water pressure to maintain the proper injectionrate of additive into output water dispensing line 130.

Pump motor 116 can be a permanent magnet DC motor that can be powered bya 12 Volt DC source. This may be preferable for a vehicle mounted ormobile fire suppressant delivery system 100 that includes a 12 Voltbattery and alternator. In some embodiments, a gearbox can be used tocouple pump motor 116 to additive pump 112. For example, a 3 to 1gearbox can be used to limit the speed of pump motor 116 to a maximum of600 RPM. A person skilled in the art can select the amount ofdisplacement in additive pump 112, the RPM of pump motor 116, thehorsepower of pump motor 116, and the gear ratio in order to obtain thedesired mix ratio of the additive with the water.

A water system supplies a water stream to the additive system. The watersystem can include a water source 124, such as a reservoir, holdingtank, or connection to a city/municipal/building water supply (e.g. ahydrant, stand pipe, etc.). An unpressurized water source 124 willrequire a water pump 126 to pressurize the water stream. A shut-offvalve 128 can be included in the water system to start or stop the watersupply. Shut-off valve 128 can be integrated with water pump 126.Although water is used in the examples provided, it should be understoodby a person skilled in the art that other fluids can be used.

An injection quill 300 is coupled to additive dispensing line 113 whichis used to inject the additive directly into output water dispensingline 130. Injection quill 300 is positioned so that the output port ispositioned near the center of output water dispensing line 130 todeposit the additive material near the center of the water flow.Injection quill 300 also includes a check valve to prevent back flow ofwater from the water system into the additive system. Injection quill300 can also maintain the 3/4 National Pipe Thread (NPT) thread standardfor screwing injection quill 300 into the receiving water pipe. Thisallows much more flow of the high viscous material and requires lesspower to do so without having to change the receiving pipe size.

Some embodiments can also include an inline static mixer 132 coupledin-line with output water dispensing line 130 after injection quill 300that can help mix the additive with water before dispensing the mixture.The need for using an inline static mixer will depend on the materialproperties of the additive.

Referring now to FIGS. 3-6, an injection quill 300 that is improved overprior art injection quills for delivering viscous or dilatant fluids isillustrated in further detail. Injection quill 300 has a tubular mainbody 310 and a tubular quill body 320 that fits within main body 310.Injection quill 300 provides an improved fluid passage through the useof one or more ports 326, as best illustrated in the cross-sectionalview in FIG. 6. Ports 326 are located on an internal extension 324 ofquill body 320. Internal extension 324 extends into the check valvechamber 330 that is formed within main body 310.

In operation, fluid enters input port 312 of main body 310 and impingesupon valve ball 340 forcing valve spring 350 to compress. A seat 328 canbe machined into the end of internal extension 324 to fit with valvespring 350. When valve ball 340 moves and forces valve spring 350 tocompress towards seat 328, fluid enters check valve chamber 330 and thefluid flows through one or more ports 326 located on internal extension324 and through quill body 320 out injection port 322.

The end of internal extension 324 having seat 328 can be open or closedto interior of quill body 320. A closed end design forces all fluid toflow through ports 326. Internal extension 324 should be designed suchthat there are a sufficient number of ports 326 and ports 326 are of asufficient size to allow the desired additive material flow throughinjection quill 300 with low resistance. Use of ports 326 provides muchless fluid resistance than forcing fluid to flow through valve spring 50of prior art injection quill in FIG. 1.

In the embodiment illustrated in FIGS. 3-6, internal extension 324 hasfour ports 326 that each have a 0.25 inch diameter which provides 0.196square inches of total area open area for fluid to pass from main body310 through internal extension 324 to injection port 322. Internaldiameter of injection port 322 is also preferably similar to theinternal diameter of input port 312 of main body 310. This also providesfor less fluid resistance in comparison to the prior art injection quillof FIG. 1. The embodiment shown in FIGS. 3-6 has an internal quill body320 diameter of 0.5 inches and an internal input port 312 diameter of0.5 inches. Internal quill body and input port diameters provides asimilar throughput to ports 326 (i.e. a similar surface area of 0.196square inches).

Main body 310 includes two sets of threading on its outer surface thatis used to couple injection quill 300 into a system. The first set ofthreading near the input port end of main body 310 is used to couple toa pipe, hose, or tubing that supplies the additive material. The secondset of threading near the injection port end of main body 310 is used tocouple injection quill 300 to the vessel containing the fluid flow thatwill be supplied with the additive.

Another advantage of injection quill 300 over prior art injection quillsis that it can be disassembled easily to be cleaned. Main body 310includes threading on its inner surface that mates with threading on theouter surface of quill body 320. This allows quill body 320 to bescrewed or unscrewed from main body 310 for assembly or disassembly tofacilitate cleaning of injection quill 300. Main body 310 can include aset screw aperture 362 for receiving a set screw 360 to retain main body310 and quill body 320 in position and prevent unscrewing of quill body320 in operation. Injection quill 300 can also include a sealing ring364 to prevent leaks between main body 310 and quill body 320.

In some embodiments, main body 310 can include an input port body 311that can be removed from main body 310. Threading on the outer surfaceof input port body 311 mates with threading on the inner surface of mainbody 310 to allow input port body 311 to screwed or unscrewed from mainbody 310 for assembly or disassembly.

Main body 310 and quill body 320 can have reduced wall thickness of theentire quill relative to prior art injection quills. This can allow foran increase of the internal diameter of injection quill 300 from theprior art injection quill diameter of 0.308″ to an enlarged diameter0.528″ without changing the overall external dimensions.

While the exemplary embodiments have been described herein, it is to beunderstood that the invention is not limited to the disclosedembodiments. The invention is intended to cover various modificationsand equivalent arrangements included within the spirit and scope of theappended claims, and scope of the claims is to be accorded aninterpretation that encompasses all such modifications and equivalentstructures and functions.

1. A system for delivering an additive into a fluid stream, the systemcomprising: a positive displacement pump coupled to an additive sourcecontaining the additive, the positive displacement pump to pump theadditive through an additive dispensing line into an injection quillcoupled to a fluid dispensing line; a variable speed motor coupled tothe positive displacement pump to drive the positive displacement pump;a flow meter coupled to the fluid dispensing line prior to the injectionquill to determine the fluid flow rate; and a controller coupled to theflow meter and the variable speed motor to control a rate of injectionfrom the additive injecting line into the fluid dispensing line bycontrolling the variable speed motor according to the fluid flow ratefrom the flow meter.
 2. The system of claim 1 wherein the injectionquill comprises a check valve to prevent backflow into the additivedispensing line.
 3. The system of claim 2 wherein the check valvecomprises a check valve chamber, check valve ball, and a spring.
 4. Thesystem of claim 3 wherein the injection quill comprises an extensionextending into the check valve chamber, the spring and check valve ballseated axially on the extension.
 5. The system of claim 4 wherein theextension defines at least one aperture providing fluid coupling betweenthe check valve chamber and an internal passage of the injection quill.6. The system of claim 1 wherein the fluid dispensing line comprises aninline static mixer after the injection quill.
 7. The system of claim 1wherein the positive displacement pump is a gear pump.
 8. The system ofclaim 1 wherein the positive displacement pump is a lobe pump.
 9. Thesystem of claim 1 wherein the additive injecting line comprises a checkvalve to prevent back flow into the additive injecting line.
 10. Thesystem of claim 1 wherein the fluid dispensing line is coupled to awater pump and water tank of a fire truck.
 11. The system of claim 1wherein the fluid dispensing line is coupled to a building water supplyand the water dispensing line feeds a building fire sprinkler system.12. The system of claim 1 wherein the controller comprises aprogrammable logic controller and a motor controller coupled to themotor.
 13. An injection quill for injecting an additive into a fluidstream, the injection quill comprising: a main body having: an inputport for receiving the additive; a check valve chamber formed within themain body coupled to the input port, the check valve chamber containinga valve ball biased in a closed position by a valve spring; and a quillbody having: an injection port for insertion into the fluid stream; aninternal extension that extends into check valve chamber, the internalextension having at least one port that couples the check valve chamberto the injection port.
 14. The injection quill of claim 13 wherein theinternal extension provides a seat for positioning the valve spring onan end of the internal extension disposed within the check valvechamber.
 15. The injection quill of claim 13 wherein the internalextension has an internal diameter at least as large as an internaldiameter of the input port.
 16. The injection quill of claim 13 whereinthe main body has threading on an inner surface that mates withthreading on an outer surface of the quill body to allow fordisassembly.
 17. The injection quill of claim 16 wherein the main bodyhas a set screw aperture for receiving a set screw to retain main bodyand quill body in fixed engagement.
 18. The injection quill of claim 13wherein the main body has threading on the outer surface near an outputport end of the main body and threading on the outer surface near aninjection port end of the main body, the threading for coupling theinjection quill to an additive dispensing line and a water dispensingline.